Most Challenging and fun mmorpg?

I've played WoW for a good 2 years, got bored of it after getting a few 80s. I've played Guild Wars and beat all campaigns. I've played Warhammer Online and thought it was too easy. I've played EQ2 and didn't like the fighting styles, and the variety of choices. I've played Lord Of The Rings Online, I liked it, but my computer broke down and I settled for a laptop (can run most games on high graphics, like GW and WaR). So now I've played a few of the best mmorpgs out there. I need another choice. And to you guys out there who say get a life, its for the christmas break when im bored and I want to complete a challenge. Thanks in advance